combine first 3 ingredients in large bowl. add hash brown potatoes. stir well, spread evenly in greased 12 inch pizza pan, pressing with back of spoon to form rim around edge. bake in 450° oven for 20 to 25 minutes until firm. heat cooking oil in large frying pan on medium. add ground beef and onion. scramble - fry for about 10 minutes until beef is no longer pink. drain. addflour, stir well. add next 5 ingredients.heat and stir for about 5 minutes until boiling and thickened. remove from heat. sprinklr 1/2 of cheese. sprinkle with remaining cheese. bake for 4 to 5 minutes until cheese is melted and bubbling, cuts into 8 wedges.